INGENUITY AND LUXURY 



tematic change in the nomenclature. This revolu- 

 tionary change was relatively easy in the case of chem- 

 ical terms, since most of them were unknown to the 

 generality of people at best, and the scientists were 

 eager to accept the new classification. 



The case was very different with the names of gems. 

 The names of a great majority of them were known 

 even to most very ignorant persons. And as is always 

 the case under these circumstances, these popular 

 names cling to them, even though the gem experts 

 have arranged a new nomenclature that approaches 

 at least a scientific classification. 



PRACTICAL TESTS 



It is apparent from the confusion of names, and con- 

 fusion of colors of the various gems, where a mistake 

 might cost thousands of dollars, that the gem expert 

 must have at his command some very accurate tests 

 -infallible tests, indeed to insure against them. The 

 first, most valuable, and absolutely essential one 

 of these, is that of trained observation a faculty 

 developed only by the handling of countless numbers 

 of cut and uncut gems. In this manner, and in this 

 manner only, can the expert learn to identify most 

 gems without resorting to the tests known to the science 

 of mineralogy. In doubtful cases, however, he for- 

 tifies his opinion by elaborate tests which have been 

 developed by modern science. One of these is af- 

 forded by the science of crystallography, the knowl- 

 edge of the various-shaped crystals as formed in the 



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